I used to have one Brassia before in 2010. Brassia Rex 'Waiomao Spotless' Quite a beauty, however, I really have a hard time with humidity. It did manage to bloom in June of 2010 indoors by our west facing window, but the pseudobulbs are just wanting more humidity got wrinkly fast. I have to admit I was really new with orchids then, so ambitious of me to try it, but it was a good challenge, and I learned a lot, sadly after it has bloomed it went downhill. Really prefers being warm and humid. I was also not sure how to handle it come winter time, so I ended up with just 2 pbs, one totally leafless and eventually kaput.
So is it hard to grow, maybe, it really just depends on the care you can provide as long as you keep it very moist and warm all the time. It is one very thirsty orchid for sure, especially in my very dry area.
